May 29, 2015




Clinical Hub,Tools & Resources,UWHC Lab Test Directory,Toxicology


Gabapentin (HCGABA) Toxicology Lab Test

Name: Gabapentin

Test Name: Gabapentin

Health Link Test Code: HCGABA

LIS Test Code: GABA

CPT Code(s): 80171

Methodology: Liquid Chromatography

Clinical Information:


Days Performed: Mon-Fri, dayshift.

In-Lab Turnaround Time: 2 days.

Specimen: Blood

Collection Container: Red top

Collection Instructions:

Collect specimen for trough level prior to next dose.

Collection Volume: 2 mL

Pediatric Collection Volume: 1.5 mL

Stability Ambient:

14 days

Stability Refridgerated:

14 days

Stability Frozen:

14 days

Sample Analyzed: Serum

Testing Volume: 1 mL

Pediatric Testing Volume: 0.5 mL

Specimen Processing:

Centrifuge. Transfer cell-free serum to plastic vial. Refrigerate.

Specimen Transport:

Transport specimen to laboratory. Transport with coolant pack if coming from clinic location.

Unacceptable Criteria:

Specimens collected in red cap with yellow ring (SST) tubes are not acceptable.


Definitive therapeutic concentration for gabapentin has not been established. A serum concentration of 5.0-15.0 mcg/mL is generally considered to be therapeutic for individuals 18 years old and up. Steady-state concentrations are nearly proportional to dose with maximum levels in the ranges of 3.0-5.0 mcg/mL, 4.4- 6.6 mcg/mL, and 6.0-11.0 mcg/mL, respectively, for doses of 300, 400 and 600 mg three times daily. Trough levels range from 1-10 mcg/mL at doses of 300, 400 and 600 mg three times daily.

Interpretation Type: Interpretive Guidelines

Additional Information:

Result of "BELOW DETECTION" indicates that the result is below the method detection limit of 0.1 mcg/mL. 


This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories.  This test meets the standards for clinical testing.  This test should not be regarded as investigational or for research use.  The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.